Relationship of Plant Density and Plant Height with Wild Blueberry Fruit Yield

摘要

Wild blueberries are commercially grown in the Maine State of United States and in Quebec and the Atlantic Provinces of Canada. The improved management practices using selective herbicides, fungicides and fertilizers have resulted in improved plant health, density and height but with inconsistent fruit yield increases. This study was designed to examine the effect of plant density and plant height on wild blueberry fruit yield. Plant density recorded from 6 different wild blueberry fields in Nova Scotia and New Brunswick was classified into 4 different levels (< 37 plants, 37 < plants < 56, 56 < plants < 74 and > 74 plants per 0.1 m2). The measured plant height was also categorized into 4 different levels which were < 18, 18 < height < 23, 23 < height < 28, > 28 cm.The Experiment was planned as a 4 x 4 factorial design with three complete randomized blocks (years) as replicates. A commercially available mechanical wild blueberry harvester was used to collect the yield data from selected yield plots in each field. Fifty-four yield plots, 3 m in length and 0.91 m in width, were made in the path of the operating harvester to collect the data. The plant height and plant density were estimated prior to the harvesting of the yield plots in selected fields. The harvesterwas operated at a ground speed of 1.6 km h1 and 28 rpm to harvest plots. Yield from each plot was collected manually and weighed. Wild blueberry fruit yield collected from each plot was the response variable for subsequent statistical analysis. Resultsof analysis of variance showed significant effect of plant height and plant density on fruit yield, however, interaction effect of both factors was found to be non-significant. Significant main effect suggested multiple means comparison (MMC) to identifybest level of plant height and density for optimum fruit yield. Least square means was used as MMC and the results indicated significantly higher yield (6889.19 kg ha1) in the areas of field where the plant density was >74 plants per 0.1 m2. On the other hand, the plant height ranging 18 < height 2 23 cm found to be the optimum height to maximize berry yield (7026.42 kg ha-1). On the basis of results it can be concluded that maximum berry yield can be obtained by increasing the plant density beyond 74plant per 0.1 m2 and maintaining the plant height within the suggested level (18 < height < 23 cm).